1. Field of the Invention
The present invention is generally related to optical interconnect and transport systems. More particularly, aspects of the invention are directed to non-blocking optical circuit switching modules.
2. Description of Related Art
Cloud computing and its applications are effecting a qualitative shift in the way people communicate and share information. The underlying computer networks that support cloud computing can be divided into two major categories: intra-datacenter and inter-datacenter. An intra-datacenter network interconnects the computing infrastructure (e.g., servers, disks) within the same building or among different buildings of a datacenter campus. An inter-datacenter network employ connections from metropolitan to long-haul reach interconnecting multiple datacenters distributed at different geographic locations. Many, if not most modern high-speed data links use optical transmission technologies via optical fibers for both intra- and inter-datacenter networks.
Currently, most of the actual computing and storage underlying the Internet and cloud computing takes place in warehouse-scale data center buildings. Similarly, most of the long-haul links transferring data and requests back and forth between end users and data centers are switched through Internet points of presence (“POP”). Both environments transfer a tremendous amount of data between individual computers and the switches and routers responsible for getting the data to its destination. This bisection bandwidth is often measured in the hundreds of terabits/second in individual data centers and POPs and is expected to soon surpass the petabit/second mark. Managing this fiber interconnect can be a significant challenge from a planning and deployment perspective. Furthermore, re-fibering an existing deployment, for instance to expand capacity, is a very labor-intensive process that can be mistake-prone. Consider, for instance, the challenges of physically rewiring a fiber plant consisting of multiple tons of short (e.g., less than 300 m) optical fiber patch cords measuring hundreds of miles in total length. Given this daunting task, re-fibering may not even be attempted in many situations.
Fiber infrastructure is typically deployed, organized and interconnected using passive fiber patch panels. These patch panels are made of arrays of passive fiber mating connectors. Therefore, network topologies are often built in a manual and static fashion. Often, there is neither active power monitoring for fault detection nor troubleshooting, nor is there a capability to automatically protect against failures. Change requests to the patch panel connectivity, e.g., to expand bandwidth capacity or to recover from connection failures, would require local on-site access and manual rewiring. This manual, labor intensive process can stretch across multiple days because of access approval and travel to remote locations, thus leading to long mean-time-to-repair (“MTTR”) and network performance degradation.
Optical circuit switching (“OCS”) has been one approach to address the above issues. OCS serves as a non-blocking active patch panel that can be controlled remotely and programmed to set up connections between any ports. It is typically implemented through mechanical switching mechanism and direct light beams between different ports either in free space or through physical connections. However, such OCS architectures may have a limited number of ports or may have slow switching speeds.